How do I explode equal length strings into Pandas DataFrame columns (without empty column)

Question

I have a data frame with strings of equal length (10). I want to "explode" this column into 10 columns. No matter what solution I try, there is a leading empty column. Existing solutions give me this problem, so needless to say existing answers to this question are not satisfactory.

import pandas as pd

df = pd.DataFrame(['tenletters', 'alsotenten', 'letter10!!', 'ten10lette'], 
    columns=['col1'])

df2 = pd.DataFrame(df['col1'].str.split('').tolist())

  0  1  2  3  4  5  6  7  8  9 10 11
0    t  e  n  l  e  t  t  e  r  s   
1    a  l  s  o  t  e  n  t  e  n   
2    l  e  t  t  e  r  1  0  !  !   
3    t  e  n  1  0  l  e  t  t  e

How can I do this the proper way (i.e., without a leading empty column)?

Andy L. · Accepted Answer · 2020-05-14 18:45:54Z

3

Use map

df_final = pd.DataFrame(df['col1'].map(list).tolist())

Out[44]:
   0  1  2  3  4  5  6  7  8  9
0  t  e  n  l  e  t  t  e  r  s
1  a  l  s  o  t  e  n  t  e  n
2  l  e  t  t  e  r  1  0  !  !
3  t  e  n  1  0  l  e  t  t  e

answered May 14, 2020 at 18:45

Andy L.

25.3k4 gold badges20 silver badges30 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

r.ook · Accepted Answer · 2020-05-14 18:52:18Z

1

>>> pd.DataFrame(df['col1'].apply(list).tolist())
   0  1  2  3  4  5  6  7  8  9
0  t  e  n  l  e  t  t  e  r  s
1  a  l  s  o  t  e  n  t  e  n
2  l  e  t  t  e  r  1  0  !  !
3  t  e  n  1  0  l  e  t  t  e

edited May 14, 2020 at 18:52

answered May 14, 2020 at 18:43

r.ook

13.9k2 gold badges26 silver badges41 bronze badges

1 Comment

Nicolas Gervais Over a year ago

the .values seems redundant

Ch3steR · Accepted Answer · 2020-05-14 20:14:25Z

0

You use pd.Series.apply

df.col1.apply(lambda x: pd.Series(list(x)))

   0  1  2  3  4  5  6  7  8  9
0  t  e  n  l  e  t  t  e  r  s
1  a  l  s  o  t  e  n  t  e  n
2  l  e  t  t  e  r  1  0  !  !
3  t  e  n  1  0  l  e  t  t  e

You can try this for fun. (Not a performant solution)

Using pd.Series.str.extractall

df.col1.str.extractall(r'(.)').unstack()

       0
match  0  1  2  3  4  5  6  7  8  9
0      t  e  n  l  e  t  t  e  r  s
1      a  l  s  o  t  e  n  t  e  n
2      l  e  t  t  e  r  1  0  !  !
3      t  e  n  1  0  l  e  t  t  e

Note: The column is MultiIndex to make it a single-level df.columns = d.columns.get_level_values(1)

edited May 14, 2020 at 20:14

answered May 14, 2020 at 19:57

Ch3steR

20.8k4 gold badges34 silver badges66 bronze badges

Collectives™ on Stack Overflow

How do I explode equal length strings into Pandas DataFrame columns (without empty column)

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related